Are some V-brakes harder to adjust?

[Rob Northcott]

Just realised my first post has got a bit waffly, so I'd better introduce myself first!
I've been cycling all my life and joined the CTC in 1988 (when I was 19) when I was after their suggested LEJOG routes. My riding was mostly long-distance touring and a bit of local club time-trialling. Got into a bit of mountain-biking while at university but never raced. I don't have an MTB anymore - all my off-road riding, including racing (mostly xc enduros and 24hr), is on unicycles. My wife and I bought a tandem in the late 90s and used it for club rides and quite a few tours of France, including one from home (Dartmoor) to Monaco. Not so much anymore after our daughter was born (although hopefully she'll be coming with us in a few more years). Recently I bought a Focus Wasgo hub-geared bike (only cost me about £250 on the Ride to Work scheme) to use on my commute in the winter and save my recently refurbished Mercian from the worst of the grot. It's working really well after a few modifications (changed comedy city-bike stem and bars and removed all the Euro-sillies like kickstand) and has done a thousand or so miles now. I'm very happy with it (especially for the money) apart from the brake setup...

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The V-brakes on my winter commuting bike are a real pain to keep adjusted properly. They'll work fine for a few days then seem to become "mushy" and snatchy on the front and almost useless on the back.

The only other bike with V-brakes I've had experience with is my wife's MTB (all our other bikes have been calipers, cantis or Maguras) which has similarly inexpensive V-brakes that have always been extremely easy to set up and just work with no messing about. That bike gets regular use on rocky, gritty, wet trails so it's not that it has an easier life - in fact the opposite is probably true.

My brakes are Avid Single Digit 3 (so pretty cheap), Clarkes blocks, Rigida Sphinx 700c rims.
My wife's MTB has Tektro brakes (not sure of the model but they weren't expensive) with the same Clarkes blocks and I think also Rigida rims.

It's tempting to try some other "better" V-brakes on my bike, but without raiding my wife's bike I've got nothing to try without actually buying a new set, which I don't really want to do unless it would be known to solve the problem (i.e. if experienced V-brake users say Single Digit 3s are rubbish). Or is it just a case of messing about with washers to get the blocks to contact the rim at different angles of the brake arm's swing? With the two standard thickness washers that come with blocks, the thick one is way too thick so I'm using the thin one.

It's annoying enough that I don't mind throwing a few quid at it if that's the solution, but not if it just needs setting up differently - although I've never had this much problem with any brake set before :/

Rob

[DaveP]

Thats a bit of a puzzler!
I use v brakes. I have to say that I find them much easier to set up than cantilevers. I've encountered problems caused by poor quality blocks (easily sorted!) and bendy brake arms (still easily sorted but less cheaply!) but the resulting lack of performance is usually constant. The sort of fading you describe leads me to wonder if you might be getting a build up of dirt on the blocks and rims.
When they go, what exactly do you have to do to get them working again?

[Rob Northcott]

Thanks for the reply Dave. It is indeed very odd - cleaning the rims doesn't help (apart from the obvious, but not with this problem) - it just seemed to work well for a bit after I'd readjusted the blocks and generally fiddled with it. I had another look at it yesterday (it's next to my desk at the office and it was a slow day!) and I'm starting to think it's down to the cable routing. The front brake was set up with the "noodle" curving forwards, almost horizontal, which did give a nice shallow bend to the cable, but on close inspection I think it was levering the noodle holder up a bit so the cable between the brake arms wasn't quite straight until pulled tight. I reckon that's what caused the bizarre feel to the brakes, and possibly varied depending on how the noodle settled. I temporarily encouraged the cable to go in a tighter S-bend close to the head tube so now the noodle is almost vertical and not resting on the noodle holding bit of the brake and it seemed a lot better on the ride home yesterday.

I'm using the unicycle for the next couple of days, but I'll route the cable more permanently at the weekend and when I get back on the bike next week I'll report back - but I think I might have got to the bottom of it.

Rob

[AlbionLass]

When I bought my hybrid with V-brakes last year I was disappointed at the spongy feel and lack of decent braking. No amount of adjustment improved matters. Upon close inspection there was a spring housed within a plastic barrel at the noodle end of the cable with meant that the brakes couldn't be applied with any force, the spring meant the brakes would only go on very gradually. I'd not seen anything like this before and since I removed the springs the brakes have worked really well.

[Rob Northcott]

When I bought my hybrid with V-brakes last year I was disappointed at the spongy feel and lack of decent braking. (...snip...) there was a spring housed within a plastic barrel at the noodle end of the cable with meant that the brakes couldn't be applied with any force

I think those are meant to stop people new to cycling from over-braking and flying over the bars (although I reckon it would be safer to learn to control the brakes rather than nobble them so they don't work properly!). Mine hasn't got those.

Further to my last post, I did actually use the bike this morning (too windy for the unicycle to be enjoyable ) and the change of cable routing does seem to have solved the problem - the front brake now has proper modulation and feels how it should (apart from the silly rubber boot thing that makes it feel like the brakes touch the rim before they actually do - I can't see any reason for the boot on a bike with mudguards, so I'm going to remove it or at least trim it down so it doesn't get in the way).

The back brake is still pretty useless, but I think that's down to the usual suspects of cable stretch, block adjustment and bendy components. I'm not really worried about that for now - it was the front I was getting annoyed with.

Rob

[AlbionLass]

I changed the v-brake arms from the Tektro ones originally fitted (they had too much flex in them) to Deore ones and then when I fitted butterfly bars I changed to Deore levers too. My brakes are now really good.

[Peter Rowell]

No amount of adjustment improved matters. Upon close inspection there was a spring housed within a plastic barrel at the noodle end of the cable with meant that the brakes couldn't be applied with any force, the spring meant the brakes would only go on very gradually.

Is this the fitting which is used to adapt "hooded levers" to use the Vee brakes with drop bars? I use "Al Honga" V-type brakes, they seem to have better return springs than the Shimano Vee Brakes. I have them on downhill bars with the short levers, I can still lift the rear wheel off the road when braking.

[Rob Northcott]

Over the weekend I cut the rubber boots down so they don't have to be compressed to apply the brakes. They were actually very thick and stiff - much less compressible than the ones on my wife's bike (which is the only other v-braked bike I've had experience with).

I think that was causing most of the remaining problem - I've now got absolutely superbly strong brakes, both front and rear. So, changing the cable routing sorted the random adjustment problem and shortening the rubber boots restored the strength. Mission accomplished without spending any money

It's weird how the rubber boots were so thick and hard to compress on my brakes. The ones on my wife's Tektro brakes are much thinner and bendier, and although they need to be compressed slightly to apply the brakes, they don't produce a noticeable resistance. The thick boots aren't another variation of the "stop new cyclists braking too hard" thing are they? I thought that was normally done using a spring like AlbionLass described.

Anyway, I'm happy with the way it's working now.

Rob

[Ray]

I found this old thread while wondering about the supposed function of the rubber boots on (mini-) V brakes.

What are they for? When my brakes are adjusted correctly in relation to the clearance between blocks and rim the boot doesn't even cover the full length of the straddle cable. The boot on the front brake split a few weeks ago, so I threw it away (the boot, not the brake!). No apparent effect on braking. OK, the cable is now exposed to the elements, but there are great lengths of exposed brake and gear cables on most bikes with no apparent detriment.

Any thoughts?

Ray

[Rob Northcott]

I'd forgotten about this thread - the wonders of email notification!
I think the boots are intended to keep muck out of the noodle, but they seem pretty pointless to me, certainly on a road bike with mudguards. I'm still using that bike BTW, with the same brakes. No problems since I cut the boots down.

[willcee]

As someone who cut his teeth working with a friend who sold hundreds of cheap rebuilt machines to local university students, i picked up a lot when working at this sort of BSO detritus.. i remain convinced that getting cheap V braked machines to brake well and without rim rub ,without good parts... is a black art.. i rarely use the black rubber parts, i nearly always recable esp. the rear cable, and care has to be used while setting brakes to rim heights and angles ime it has to be done at eye level.. the most difficult problem imo is having equal pull on the v arms , even new they often sit lop sided..i found that new cables and increased tension, but not always equal side to side ....had a measurable effect .. but on cheap stuff it can be a lottery.. will

[mill4six]

My son's Carrera CX1.0 suffers terribly to the extent that I've just bought him a disc braked subway. We could never get the Vee brakes to work satisfactorily for more than a few weeks and I was terrified he'd get killed. Now that he's gone to uni I can't be checking his bike all the time. I wonder if the CX1.0 doesn't have cantilever brake mounting posts with vees fitted and therefore wrong geometry. In any case they're not good brakes. I'd love to sort it though because as cheap as it was the steel frame and upright riding position are incredibly comfortable and it would make a superb tourer particularly as it would accept my 700c hub dynamo wheel currently on my Ribble audax.

[531colin]

Modern brake bosses are about 80mm apart. Modern cantis will fit them, or vees.
maybe 15 years ago, the front bosses were closer together, maybe 65mm....only old cantis will fit them properly without all sorts of fun getting the pad/rim angle right by using half-worn pads, and such.

[meic]

I think that if the boot is getting compressed then you are probably using the brakes set up out of their optimum range.

The answer would be to move your brake pads further out on their stalks, so as to keep the legs of the V brakes further apart when the pads touch the rim. Before considering cutting the boot.
Assuming that you have enough length on the stems of the pads or can arrange the washers enough on a threaded type.
My Tektro miniVs had a stated limit for the exposed length of the wire.